The likelihood of some water quality issues is typically reducing with the onset of cooler conditions. Basin rivers and storages are nutrient rich and conditions remain favourable for blue green algae outbreaks.
Summary of key water quality issues
Water quality in the Murray–Darling Basin is monitored by individual Basin state governments. Specific water quality alerts are issued by respective states.
- Low dissolved oxygen: In the lower Darling (Baaka), dissolved oxygen levels generally remain above critical ecological thresholds as conditions have become cooler. Low dissolved oxygen levels are no longer being recorded immediately downstream of Hume Dam. This is due to Lake Hume de-stratifying with the onset of cooler weather. This means that as the water cools, the entire water column becomes mixed and low oxygen levels are no longer an issue with the water that is released.
- Blue-green algae: There is currently a risk of blue-green algae across most parts of the Murray–Darling Basin, particularly in New South Wales and Victoria. An advisory notice for blue-green is also currently in place for Lake Alexandrina in SA. For the latest information on blue-green algae alerts, contact the relevant state government contacts via the Getting information about current algal blooms page of our website.
- Elevated Salinity: Some of the Menindee Lakes and parts of the lower Darling River (Baaka) are seeing elevated salinity levels. This is not expected to have any significant impacts across the border into South Australia.
| Location | Algal blooms | Acid sulfate soils | Blackwater | Elevated Salinity | High turbidity | Low dissolved oxygen |
| Coorong | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely |
| Lower Lakes | Likely | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely |
| Murray (SA below Lock 1) | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely |
| Murray (Waikerie to Lock 1) | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely |
| Murray (SA border to Waikerie) | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely |
| Murray (Lock 10 to SA border) | Possible | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely |
| Murray (Euston to Lock 10) | Possible | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely |
| Murray (Yarrawonga to Euston) | Possible | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely |
| Murray (Hume to Yarrawonga) | Possible | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely |
| Murray (upstream of Hume Dam) | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely |
| Edward–Wakool | Possible | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely |
| Murrumbidgee (Upper) | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely |
| Murrumbidgee (Mid) | Possible | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely |
| Murrumbidgee (Lower) | Possible | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely |
| Lachlan (Upper) | Possible | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely |
| Lachlan (Lower) | Possible | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely |
| Grampian–Wimmera–Mallee | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely |
| Campaspe River | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely |
| Avoca–Loddon River | Possible | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely |
| Goulburn–Broken | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely |
| Ovens | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely |
| Kiewa | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely |
| Lower Darling/Baaka (Menindee to Burtundy) | Almost certain | Unlikely | Unlikely | Likely | Unlikely | Unlikely |
| Menindee Lakes | Almost certain | Unlikely | Unlikely | Likely | Unlikely | Unlikely |
| Barwon–Darling | Possible | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely |
| Upper Macquarie–Cudgegong | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely |
| Lower Macquarie–Castlereagh–Bogan | Possible | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely |
| Namoi | Possible | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely |
| Gwydir | Possible | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely |
| Border Rivers (including Moonie) | Possible | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely |
| Condamine–Maranoa | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely |
| Culgoa–Balonne–Narran | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely |
| Paroo | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely |
| Warrego–Nebine | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely | Unlikely |